Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262594AbVDLWeC (ORCPT ); Tue, 12 Apr 2005 18:34:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262233AbVDLWby (ORCPT ); Tue, 12 Apr 2005 18:31:54 -0400 Received: from pat.uio.no ([129.240.130.16]:60388 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S262986AbVDLW0t (ORCPT ); Tue, 12 Apr 2005 18:26:49 -0400 Subject: Re: NFS2 question, help, pls! From: Trond Myklebust To: Xin Zhao Cc: linux-kernel@vger.kernel.org In-Reply-To: <4ae3c1405041212223ee0609e@mail.gmail.com> References: <4ae3c1405041212223ee0609e@mail.gmail.com> Content-Type: text/plain Date: Tue, 12 Apr 2005 15:26:35 -0700 Message-Id: <1113344795.10420.125.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit X-UiO-Spam-info: not spam, SpamAssassin (score=-4.797, required 12, autolearn=disabled, AWL 0.20, UIO_MAIL_IS_INTERNAL -5.00) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1156 Lines: 29 ty den 12.04.2005 Klokka 15:22 (-0400) skreiv Xin Zhao: > I have very very fast network and is testing NFS2 over this kind of > network. I noticed that for standard work like read/write a large > file, compile kernels, the performance of NFS2 is good. But if I try > to decompress kernel tar file. The standard ext2 takes 28s while NFS2 > takes 81s. Also, if I remove the kernel source code tree, ext2 takes > 19s but NFS2 takes 44s. > > Why? (You can assume that network is very fast. ) Is there any > improvements in NFS3/4 on this issue? If so, how? NFSv2 requires the server to immediately write all data to disk before it can reply to the RPC write request (synchronous writes). NFSv3 and v4 both have the ability to cache writes safely. The following paper http://www.netapp.com/ftp/NFSv3_Rev_3.pdf has full details on how and why. Cheers, Trond -- Trond Myklebust - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/